Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
  • F16H61/04—Smoothing ratio shift
  • F16H61/0403—Synchronisation before shifting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
  • F16H61/68—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for stepped gearings
  • F16H61/684—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for stepped gearings without interruption of drive
  • F16H61/688—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for stepped gearings without interruption of drive with two inputs, e.g. selection of one of two torque-flow paths by clutches
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H2306/00—Shifting
  • F16H2306/40—Shifting activities
  • F16H2306/48—Synchronising of new gear

Definitions

• the invention relates to a method for controlling one or more synchronizers in a vehicle gearbox, especially a motor vehicle, during a gear downshift, so as to obtain torque to accelerate the vehicle.
• the known state of the art usually seeks to optimize the control of the synchronizers of a gearbox during a gearshift in order to respect the maximum power allowed by each synchronizer. This is for example the case of documents FR 2 915 259 and US 6,896,641.
• the subject of the invention is a method of controlling a synchronizer for synchronizing a first gear geared onto a first gearbox primary shaft with a secondary shaft subjected to a gearbox.
• secondary shaft torque exerting a force on the synchronizer which generates a synchronization torque equal to said force multiplied by a synchronous torque capacity of the first gear, wherein said force is limited to the secondary shaft torque divided by said couple capacity.
• said secondary shaft is engaged with at least one vehicle wheel on which is applied a torque to the wheel equal to the secondary shaft torque multiplied by a bridge ratio of transmission and limit said torque force to the wheel divided by said torque capacity and said transmission bridge ratio.
• the secondary shaft is driven by a second sprocket engrained on a second primary shaft of the gearbox which transmits a motor torque and the torque to the wheel is determined according to the engine torque and a second gear ratio .
• the secondary shaft is driven by a second pinion engrained on a second primary shaft of the gearbox which transmits a driving torque and the secondary shaft torque is determined according to the engine torque and a gear ratio. second gear.
• the invention also relates to a vehicle comprising a gearbox comprising a synchronizer for synchronizing a first pinion gear on a first primary shaft with a secondary shaft subjected to a secondary shaft torque, exerting a force on the synchronizer which generates a synchronization torque equal to said force multiplied by a synchronous torque capacity of the first gear, and an electronic device arranged to limit said force to a value equal to the secondary shaft torque divided by said torque capacity.
• said electronic device is arranged to limit said force to a value equal to a torque applied to at least one vehicle wheel engaged with said secondary shaft, divided by said torque capacity and by a transmission bridge ratio between the secondary shaft and wheel.
• the gearbox comprises a second primary shaft on which a second pinion is engrained to drive the secondary shaft so as to transmit a driving torque and the electronic device is arranged to determine the torque to the wheel depending on the engine torque and a second gear ratio.
• the gearbox comprises a second primary shaft on which a second gear is engrained to drive the secondary shaft so as to transmit a driving torque and the electronic device is arranged to determine the secondary shaft torque as a function of the engine torque and a second gear ratio.
• the single figure is a schematic view of double clutch gearbox on which is implemented the method according to the invention.
• a double-clutch gearbox like that shown in the figure, comprises two primary shafts 11, 12.
• a first clutch (not shown) is, in known manner, for connecting the first primary shaft 11 to the motor to engage the gear ratios. odd order speeds.
• a second clutch also not shown because known, is intended to connect the second primary shaft 12 to the motor to engage the even order speed ratios.
• One or more secondary shafts 21, 22 are secured in rotation with the drive wheels of the vehicle. On the secondary shaft or shafts 21, 22 are mounted free to rotate, idle gears 1, 3, 5 respectively corresponding to the gear ratios of order 1, 3, 5. Similarly, idle gears 2, 4, 6 are rotatably mounted on the secondary shaft or shafts 21, 22, corresponding to the even-order speed ratios respectively 2, 4, 6.
• Each idler gear 1, 2, 3, 4, 5, 6 can be synchronized with the secondary shaft 21 or 22 by means of a not shown synchronizer.
• the fundamental principle of double-clutch gearbox control is the arrangement of even and odd gear ratios in two gearboxes.
• a ratio is engaged in the box comprising the even ratios by synchronizing with the secondary shaft 21 or the secondary shaft 22, one of the idle gears 2, 4, 6 driven in rotation by the second primary shaft 12 which is engaged on engine.
• the odd ratio predicted for a gear change is preselected by synchronizing one of the idle gears 1, 3, 5 with the secondary shaft 21 or the secondary shaft 22 so that the primary shaft 11 of the odd ratios is driven. in rotation by the idle gear of the preselected report which is synchronized.
• a report is engaged in the box comprising the odd-numbered reports by synchronizing with the secondary shaft 21 or the secondary shaft 22, one of the idle gears 1, 3, 5 rotated by the first primary shaft 11 which is engaged on the engine.
• the pairwise ratio expected for a ratio change is preselected reciprocally by synchronizing one of the idle gears 2, 4, 6 with the shaft secondary 21 or secondary shaft 22 so that the primary shaft 12 of the even ratios is rotated by the idle gear of the preselected ratio which is synchronized.
• gearshift strategies for this type of gearbox are generally based on an interpretation of the driver's will. For example on a strong acceleration in second, preselect the gearbox not engaged on the third gear.
• a ratio is then observed between the speed of rotation of the non-engaged shaft and the speed of rotation of the engaged shaft proportional to the ratio of the idler gear engrained on the clutched primary shaft which is synchronized on the secondary shaft, and vice versa. proportional to the ratio of the idler gear engrained on the unclamped primary shaft that is synchronized to the secondary shaft.
• Shifting strategies in double-clutch gearboxes are essentially based on the interpretation of the driver's will.
• the synchronizer control is set to obtain the shortest possible synchronization time.
• the torque then imposed on the synchronizer to accelerate the pinion 1 and in fact the primary shaft 11, may in this situation be greater than the torque that the engine provides on the secondary shaft 22, with the consequence of degrading the approval of the vehicle.
• the method of the invention makes it possible to determine a maximum torque of synchronization applicable without impact on the approval of the vehicle.
• the torque supplied by the synchronizer is limited so as not to exceed the engine torque transmitted to the wheels on the 2nd gear .
• the torque C s 2nd to the wheel available to the wheel to perform the synchronization is:
• the synchronizer i iere being placed on the secondary shaft, the call synchronizing torque in requesting a torque C s (l iere) to the wheel:
• the torque imposed on the wheel by the synchronizer of l iere is therefore much higher than that provided by the engine in the second engaged with the consequence of causing inconvenience type shocks, rebounds, sudden accelerations, and others.
• the method of the invention uses an electronic device which communicates in a known manner by means of a CAN bus with the usual controllers of the vehicle, in particular that which gives the engine torque information.
• the electronic device calculates the torque at the wheel as a function of the engine torque by the formula:
• the synchronizing torque is imposed on the value of the wheel torque and the maximum force is calculated to be applied to synchronizer i iere:
• a special electronic device is not necessary if it is possible to program a computer of the gearbox so as to host a function making it possible to calculate the maximum effort F max sync driving the first synchronizer as a function of the torque to the wheel, itself predetermined according to the engine torque in 2 nd .
• the technical interest of the method and the electronic device lies in the respect of the approval during the synchronization phase of the report of the first rolling vehicle.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Control Of Transmission Device (AREA)

Applications Claiming Priority (2)

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Family Cites Families (5)

• 2010
  • 2010-01-28 FR FR1050556A patent/FR2955637B1/fr not_active Expired - Fee Related
  • 2010-12-10 EP EP10805472A patent/EP2529132A1/de not_active Withdrawn
  • 2010-12-10 WO PCT/FR2010/052667 patent/WO2011092382A1/fr active Application Filing

Non-Patent Citations (1)

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